Until recently, a patent plaintiff had its choice of bringing suit in any forum in which an accused product was sold—in practice, usually any court in the country. In addition, in the Eastern District of Texas, plaintiffs could typically join as many defendants as they cared to sue under the same set of patents in a single suit. One result was large multi-defendant patent suits in venues such as the Eastern District of Texas, in which a large number of unrelated companies found themselves together in a single patent suit.

The America Invents Act (AIA) changed the joinder rules in 2012, partly in response to the argument that large, multi-defendant cases allowed unscrupulous patent owners to trade on the defendants' litigation costs and reach artificially high settlements. The theory was that it was cheap for a patent owner to sue a lot of defendants in a single forum, perhaps one inconvenient to many of the defendants, and then to extract nuisance settlements based in part on the costs of getting out of a large and messy case in a distant place. Some also questioned the fairness of forums commonly chosen by patent owners, most typically the Eastern District of Texas. In other words, the argument went, settlements were based on procedural headaches instead of the merits of the patents.

The presence of many defendants in the suit (usually including some from the chosen venue) made it hard to transfer the case to a different venue, because no venue would be more convenient for the whole group of joined defendants. In an effort to get out of Texas, defendants began increasingly to seek transfer of venue in the Federal Circuit based on the extraordinary writ of mandamus. The Federal Circuit responded by accepting the writs and ordering the transfer of cases from the plaintiff's chosen venue to ones a defendant found more convenient (or more friendly) based on the defendant's location. Today, a defendant is far more likely to get its choice of transfer in a suit filed by a bare patent owner that does not do substantial business other than patent licensing and enforcement. District judges now grant many transfer motions, following the precedents of the Mandamus cases.